Constant horizon 3D imaging system and related method

ABSTRACT

An imaging system includes an imaging scope, a controller, a camera, and a processor. The imaging scope is selectively rotatable about a longitudinal axis relative to a horizon plane. The imaging scope has at least three optical channels, each including a respective objective that captures light. The objectives are positioned such that respective viewing direction axes of the optical channels extend at least substantially parallel to one another. The controller activates a pair of optical channels that is at least as parallel relative to the horizon plane as any other pair of optical channels. The camera generates a first image representative of light captured by a first optical channel of the activated pair of optical channels, and a second image representative of light captured by a second optical channel of the activated pair of optical channels. The processor generates a 3D image using the first and second images.

TECHNICAL FIELD

The present disclosure generally relates to an imaging system and arelated method. The present disclosure more particularly relates to aconstant horizon three-dimensional (3D) imaging system and a relatedmethod that involves an imaging scope (e.g., an endoscope, an exoscope,a borescope, etc.) and a camera.

BACKGROUND

It is known to provide an imaging system having an imaging scope (e.g.,an endoscope, an exoscope, a borescope, etc.) that captures lightreflected from an object, and a camera that converts the captured lightinto digital images. It is also known to provide 3D imaging systems thatare capable of generating 3D digital images. In such 3D imaging systems,the imaging scope includes two separate optical channels that define aseparation distance therebetween and are positionally-fixed relative tothe imaging scope. The camera generates a first two-dimensional (2D)digital image representative of light captured by the first opticalchannel and a second 2D digital image representative of light capturedby the second optical channel. The 3D digital image is generated bycombining at least portions of the first 2D digital image and the second2D digital image.

Such 3D imaging systems can be problematic in that, during rotation ofthe imaging scope relative to a real-world horizon plane (e.g., a planeperpendicular to a gravity vector), the 3D digital image displayed onthe monitor shows a corresponding rotation. That is, the horizon of the3D digital image displayed on the monitor will no longer correspond tothe real-world horizon plane. As the imaging scope is rotated, it isimpossible to maintain a 3D digital image, in particular a 3D digitalimage having a horizon that is aligned with the real-world horizonplane. The separation of the two optical channels in a directionparallel to the real-world horizon plane gets smaller and smaller, anddisappears completely when the imaging scope is rotated ninety degrees(90°) about a longitudinal axis of the imaging scope, thus making itimpossible for a user to view a 3D digital image.

Aspects of the present invention are directed to these and otherproblems.

SUMMARY

According to an aspect of the present invention, an imaging systemincludes an imaging scope, a controller, a camera, and a 3D processor.The imaging scope extends along a longitudinal axis between a proximalend portion and a distal end portion thereof. The imaging scope isselectively rotatable about the longitudinal axis relative to a horizonplane. The imaging scope has at least three optical channels, eachincluding a respective objective positioned at the distal end portion ofthe imaging scope, and each configured to capture light reflected froman object. The objectives of the at least three optical channels areannularly-spaced relative to one another and positioned such thatrespective viewing direction axes of the at least three optical channelsextend at least substantially parallel to one another. The controller isconfigured to activate, among the at least three optical channels, apair of optical channels that is at least as parallel relative to thehorizon plane as any other pair of optical channels among the at leastthree optical channels. The camera is configured to generate a first 2Ddigital image representative of light captured by a first opticalchannel of the activated pair of optical channels, and a second 2Ddigital image representative of light captured by a second opticalchannel of the activated pair of optical channels. The 3D processor isconfigured to generate a 3D digital image using the first 2D digitalimage and the second 2D digital image.

According to another aspect of the present invention, an imaging systemincludes an imaging scope, a controller, a camera, and a 3D processor.The imaging scope extends along a longitudinal axis between a proximalend portion and a distal end portion thereof. The imaging scope isselectively rotatable about the longitudinal axis relative to a horizonplane. The imaging scope has at least three optical channels, eachincluding a respective objective positioned at the distal end portion ofthe imaging scope, and each configured to capture light reflected froman object. The objectives of the at least three optical channels areannularly-spaced relative to one another and positioned such thatrespective viewing direction axes of the at least three optical channelsextend at least substantially parallel to one another. The controller isconfigured to activate, among the at least three optical channels, apair of optical channels defining a viewing horizon line that is atleast as parallel relative to the horizon plane as that of any otherpair of optical channels among the at least three optical channels. Theviewing horizon line is a line that extends perpendicularly between therespective viewing direction axes of the pair of optical channels. Thecamera is configured to generate a first 2D digital image representativeof light captured by a first optical channel of the activated pair ofoptical channels, and a second 2D digital image representative of lightcaptured by a second optical channel of the activated pair of opticalchannels. The 3D processor is configured to generate a 3D digital imageusing the first 2D digital image and the second 2D digital image.

According to another aspect of the present invention, a methodcomprising: (i) providing an imaging scope that extends along alongitudinal axis between a proximal end portion and a distal endportion thereof, the imaging scope having at least three opticalchannels, each including a respective objective positioned at the distalend portion of the imaging scope, and each configured to capture lightreflected from an object, the objectives being annularly-spaced relativeto one another and positioned such that respective viewing directionaxes of the at least three optical channels extend at leastsubstantially parallel to one another; (ii) rotating the imaging scopeabout the longitudinal axis relative to a horizon plane; (iii)activating, among the at least three optical channels, a pair of opticalchannels that is at least as parallel relative to the horizon plane asany other pair of optical channels among the at least three opticalchannels; (iv) generating a first 2D digital image representative oflight captured by a first optical channel of the activated pair ofoptical channels, and a second 2D digital image representative of lightcaptured by a second optical channel of the activated pair of opticalchannels; and (v) generating a 3D digital image using the first 2Ddigital image and the second 2D digital image.

In addition to, or as an alternative to, one or more of the featuresdescribed above, further aspects of the present invention can includeone or more of the following features, individually or in combination:

the horizon plane is an imaginary plane that is oriented perpendicularrelative to a gravity vector;

the horizon plane is oriented parallel relative to a gravity vector;

the horizon plane is non-perpendicularly offset relative to the gravityvector;

the horizon plane is selectively chosen and adjusted by a user;

the imaging scope further includes a shaft, a housing, and a window;

the shaft extends along (i.e., extends in a direction of) thelongitudinal axis of the imaging scope;

the shaft is rigid and includes a tubular shaft wall and a shaft channeldefined by an inner surface of the shaft wall;

the outer surface of the shaft wall defines a diameter of approximatelyfour millimeters (4 mm), five millimeters (5 mm), ten millimeters (10mm), and/or another magnitude;

the housing is integrally connected to the proximal end portion of theshaft;

the housing serves as a handle of the imaging scope that can be graspedby a user during use of the imaging scope;

the housing is releasably connected to the proximal end portion of theshaft;

the housing is not intended to serve as a handle of the imaging scope;

the window is disposed at the distal end portion of the shaft, and ismade of glass or another suitable material that is at leastsubstantially transparent;

the window is planar and is non-perpendicularly offset relative to thelongitudinal axis of the imaging scope;

multiple windows are disposed at the distal end portion of the shaft;

multiple windows disposed at the distal end portion of the shaft arearranged such that they all lie in a common plane;

multiple windows disposed at the distal end portion of the shaft arearranged such that each lies in a different respective plane;

one or more windows disposed at the distal end portion of the shaft areoriented perpendicular relative to the longitudinal axis of the imagingscope;

one or more windows disposed at the distal end portion of the shaft havea spherical or other non-planar shape;

the housing of the imaging scope houses the camera, the controller, andthe 3D processor;

at least one of the camera, the controller, and the 3D processor arehoused within the shaft of the imaging scope;

the camera is housed in the distal end portion of the shaft of theimaging scope, while the controller and the 3D processor are housed inthe housing of the imaging scope;

at least one of the camera, the controller, and the 3D processor areremotely positioned relative to the imaging scope;

the housing houses at least the camera, and the housing is characterizedas a camera housing;

the housing houses at least the camera, and the housing is characterizedas a camera head;

each of the at least three optical channels includes a respectiveobjective positioned at the distal end portion of the imaging scope;

each of the objectives has a field of view, and a light entrance surfacethat captures light reflected from an object and passed through thewindow;

the viewing direction axes of the optical channels are angularly offsetrelative to the longitudinal axis of the imaging scope (e.g., by thirtydegrees (30°), forty-five degrees (45°), sixty degrees (60°), or anothermagnitude);

the viewing direction axes each extend perpendicular to the lightentrance surface of the objective of the respective optical channel;

the orientations of the viewing direction axes vary as the imaging scopeis rotated about its longitudinal axis;

the imaging scope has an “oblique viewing” configuration and/or a “sideviewing” configuration;

the viewing direction axes are oriented parallel relative to thelongitudinal axis of the imaging scope;

the imaging scope has an “end viewing” configuration and/or an angularoffset of zero degrees (0°);

each of the at least three optical channels further includes arespective image transmission device that transmits the captured lightfrom the respective objectives of the optical channels to the camera;

each image transmission device includes a rod lens, and each transmitsthe captured light therethrough in the form of a captured light beamhaving a circular cross-sectional shape;

the image transmission devices are configured to transmit the capturedlight therethrough in the form of a captured light beam having anothercross-sectional shape that is at least partially circular (e.g., ovular,elliptical, etc.);

the imaging scope includes three (3) optical channels, four (4) opticalchannels, five (5) optical channels, six (6) optical channels, or morethan six (6) optical channels;

the imaging scope includes a plurality of light sources positionedwithin the shaft channel proximate the window;

the light sources are positioned radially between the optical channelsand the shaft wall;

the light sources are connected to the controller via wires;

the controller controls (e.g., activates, deactivates) the light sourcessuch that the light sources selectively illuminate an object byselectively emitting illumination light through the window and out ofthe distal end of the imaging scope;

the controller is configured to selectively activate one or more lightsources depending on which optical channels form the activated pair;

the controller is configured to continuously change which light sourcesare activated in order to keep up with continuous changes to whichoptical channels form the activated pair;

the camera includes at least two image sensors;

each of the image sensors includes at least a portion of alight-sensitive surface configured to receive captured light from one ofthe optical channels of the imaging scope, and each is configured togenerate a 2D digital image representative of such captured light;

a single component forms more than one image sensor;

the light sensitive surface of a CCD or another imaging device issubdivided into several predetermined portions, with each of the severalpredetermined portions forming a separate image sensor;

the number of image sensors is the same as the number of opticalchannels of the imaging scope;

the camera includes only two (2) image sensors, or another number ofimage sensors that is fewer than the number of optical channels of theimaging scope;

the image sensors are positionally fixed relative to the opticalchannels during operation of the imaging system;

each of the optical channels is permanently paired with a respectiveimage sensor;

the image sensors are rotatable relative to the optical channels duringoperation of the imaging system;

a parallel alignment of the two (2) image sensors relative to thehorizon plane remains fixed during operation of the imaging system;

the camera is a video camera, and the 2D digital images generated by theimage sensors represent one of a plurality of time-sequenced frames of adigital video;

the controller is in signal communication with the camera (inparticular, the image sensors of the camera);

during activation of an optical channel, the controller causes theoptical channel to be one from which captured light is used by thecamera to generate the 2D digital images;

light captured and transmitted through an activated optical channel issubsequently received by the light-sensitive surface of an image sensorof the camera, and the respective image sensor generates a 2D digitalimage representative thereof;

light captured and transmitted through an optical channel that has notbeen activated by the controller will not be received by an image sensorof the camera;

the image sensor will not generate a 2D digital image representative oflight captured and transmitted through an optical channel that has notbeen activated by the controller;

the image sensor will generate a 2D digital image representative oflight captured and transmitted through an optical channel that has notbeen activated by the controller, but the 3D processor will not use that2D digital image to generate a 3D digital image;

the controller activates a particular optical channel by instructing acorresponding image sensor of the camera to generate a 2D digital imagerepresentative of the light received from the particular opticalchannel;

the controller activates a particular pair of optical channels bysending instructions to the camera that causes movement of the imagesensors relative to the optical channels until the image sensors arealigned with the particular pair of optical channels;

a gravity sensor sends a data signal to the controller regarding theorientation and/or movement of the imaging scope relative to thedirection of a gravity vector, and the controller uses such data toactivate a pair of optical channels;

the horizon plane is chosen and/or determined by the controller based onthe data signal received from the gravity sensor;

the gravity sensor is positioned within the housing of the imagingscope;

the gravity sensor is positioned within the shaft of the imaging scope,or in another location where the gravity sensor will be rotated togetherwith the imaging scope and/or the optical channels thereof;

the gravity sensor is in the form of a three-axis acceleration sensor;

the gravity sensor is configured to be turned off manually and theorientation of the horizon plane selectively chosen and adjusted by auser;

additional sensors like magnetometers and gyroscopes are used to improveor correct the measurement of such a gravity sensor;

the controller is configured to perform known digital image erecting anddigital flip-mirror functions on the 2D digital images beforetransmitting the same to the 3D processor;

the functionality of the controller is implemented using mechanical,analog and/or digital hardware, software, firmware, or a combinationthereof;

the controller performs one or more of the functions by executingsoftware, which is stored in a memory device;

the 3D processor is in signal communication with the controller, andreceives the 2D digital images from the controller and processes the 2Ddigital images in a known manner to generate a 3D digital image;

the 3D processor is configured to calculate a depth map using the 2Ddigital images;

the depth map provides a calculation of the relative distances from thewindow at the distal end of the imaging scope to various objects acrossthe field of view of the imaging scope;

the parallax between the 2D digital images allows the 3D processor tocalculate such a depth map;

the functionality of the 3D processor is implemented using analog and/ordigital hardware, software, firmware, or a combination thereof; and

the 3D processor performs one or more of the functions by executingsoftware, which is stored in a memory device.

These and other aspects of the present invention will become apparent inlight of the drawings and detailed description provided below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 schematically illustrates an imaging system including an imagingscope, a controller (see FIG. 2), a camera (see FIG. 2), and a 3Dprocessor (see FIG. 2).

FIG. 2 schematically illustrates the imaging system of FIG. 1.

FIG. 3 schematically illustrates a distal end portion of the imagingscope of FIG. 1.

FIG. 4 schematically illustrates the distal end of the imaging scope ofFIG. 1 in a first rotational position.

FIG. 5 schematically illustrates portions of the imaging scope of FIG. 1in the first rotational position.

FIG. 6 schematically illustrates the distal end of the imaging scope ofFIG. 1 in a second rotational position.

FIG. 7 schematically illustrates portions of the imaging scope of FIG. 1in the second rotational position.

FIG. 8 schematically illustrates the distal end of the imaging scope ofFIG. 1 in a third rotational position.

FIG. 9 schematically illustrates portions of the imaging scope of FIG. 1in the third rotational position.

FIG. 10 schematically illustrates the imaging system of FIG. 1 arrangedsuch that the horizon plane is parallel to a gravity vector.

FIG. 11 schematically illustrates another imaging system in which thecamera is positioned in the distal end portion of the shaft of theimaging scope.

FIG. 12 schematically illustrates a distal end portion of an imagingscope having four (4) optical channels.

FIG. 13 schematically illustrates a distal end portion of an imagingscope having five (5) optical channels.

FIG. 14 schematically illustrates a distal end portion of an imagingscope having six (6) optical channels.

DETAILED DESCRIPTION

Referring to FIGS. 1 and 2, the present disclosure describes an imagingsystem 10 and a related method. The imaging system 10 includes animaging scope 12, a controller 14 (see FIG. 2), a camera 16 (see FIG.2), and a 3D processor 18 (see FIG. 2).

Referring to FIGS. 2 and 3, the imaging scope 12 (e.g., an endoscope, anexoscope, a borescope, etc.) extends along a longitudinal axis 20between a proximal end portion and a distal end portion thereof. Theimaging scope 12 is selectively rotatable about the longitudinal axis 20relative to a horizon plane 26. The imaging scope 12 has at least threeoptical channels 28, 30, 32, each including a respective objective 34,36, 38 (e.g., an objective prism, an objective lens, etc.) positioned atthe distal end portion of the imaging scope 12, and each configured tocapture light reflected from an object (e.g., an internal body cavity ofa patient). The objectives 34, 36, 38 are annularly-spaced relative toone another and are positioned such that their respective viewingdirection axes 40, 42, 44 (see FIG. 3) extend at least substantiallyparallel to one another. The controller 14 (see FIG. 2) is configured toactivate, among the at least three optical channels 28, 30, 32, a pairof optical channels that is at least as parallel relative to the horizonplane 26 as any other pair among the at least three optical channels 28,30, 32. The activated pair of optical channels defines a viewing horizonline 46 (see FIGS. 4, 6, 8) that is at least as parallel relative to thehorizon plane 26 as that of any other pair among the at least threeoptical channels 28, 30, 32. The viewing horizon line 46 is an imaginaryline that extends perpendicularly between the respective viewingdirection axes 40, 42, 44 (see FIG. 3) of the optical channels includedin the activated pair of optical channels. The camera 16 (see FIG. 2) isconfigured to generate a first 2D digital image representative of lightcaptured by a first optical channel of the activated pair of opticalchannels, and a second 2D digital image representative of light capturedby a second optical channel of the activated pair of optical channels.The 3D processor 18 (see FIG. 2) is configured to generate a 3D digitalimage using the first 2D digital image and the second 2D digital image.In some embodiments, the imaging system 10 further includes a monitor(not shown) on which the 3D digital image is displayed.

In the embodiment illustrated in FIGS. 1-9, the horizon plane 26 is animaginary plane that is oriented perpendicular relative to a gravityvector 48. In other embodiments, such as that illustrated in FIG. 10,the horizon plane 26 can be oriented parallel relative to a gravityvector 48. In still other embodiments, the horizon plane can benon-perpendicularly offset relative to the gravity vector 48, and/or theorientation of the horizon plane 26 can be selectively chosen andadjusted by a user (e.g., via an input device on the imaging scope 12).

Referring to FIGS. 2 and 3, the imaging scope 12 further includes ashaft 50, a housing 51, and a window 61.

The shaft 50 extends along (i.e., extends in a direction of) thelongitudinal axis 20 of the imaging scope 12. In the illustratedembodiments, the shaft 50 is rigid and includes a tubular shaft wall 52and a shaft channel 54 defined by an inner surface of the shaft wall 52.The outer surface of the shaft wall 52 defines a diameter (e.g., adiameter of approximately four millimeters (4 mm), five millimeters (5mm), ten millimeters (10 mm), and/or another magnitude).

In the illustrated embodiments, the housing 51 is integrally connectedto the proximal end portion of the shaft 50, and the housing 51 servesas a handle of the imaging scope 12 that can be grasped by a user duringuse of the imaging scope 12. In some embodiments, the housing 51 isreleasably connected to the proximal end portion of the shaft 50, and/orthe housing 51 is not intended to serve as a handle of the imaging scope12.

The window 61 is disposed at the distal end portion of the shaft 50, andis made of glass or another suitable material that is at leastsubstantially transparent. In the illustrated embodiments, the window 61is planar, and is non-perpendicularly offset relative to thelongitudinal axis 20 of the imaging scope 12. In other embodiments,there can be multiple windows disposed at the distal end portion of theshaft 50 (e.g., one window for each of the at least three opticalchannels 28, 30, 32). The multiple windows can be arranged such thatthey all lie in a common plane, or such that each window lies in adifferent respective plane. In some embodiments, the one or more windowscan be oriented perpendicular relative to the longitudinal axis 20 ofthe imaging scope 12, rather than being non-perpendicularly offsetrelative to the longitudinal axis 20 as shown in the illustratedembodiments. Also, in some embodiments, the one or more windows can eachhave a spherical or other non-planar shape.

In the embodiment illustrated in FIGS. 1-9, the housing 51 of theimaging scope 12 houses the camera 16, the controller 14, and the 3Dprocessor 18. In other embodiments, at least one of the camera 16, thecontroller 14, and the 3D processor 18 can be housed within the shaft 50of the imaging scope 12. In the embodiment of FIG. 11, for example, thecamera 16 is housed in the distal end portion of the shaft 50 of theimaging scope 12, while the controller 14 and the 3D processor 18 arehoused in the housing 51 of the imaging scope 12. In some embodiments,at least one of the camera 16, the controller 14, and the 3D processor18 can be remotely positioned relative to the imaging scope 12. In someembodiments in which the housing 51 houses at least the camera 16, thehousing 51 can additionally or alternatively be characterized as acamera housing or a camera head.

Referring to FIGS. 2 and 3, each of the at least three optical channels28, 30, 32 includes a respective objective 34, 36, 38 positioned at thedistal end portion of the imaging scope 12 (e.g., at the distal endportion of the shaft 50). In the illustrated embodiments, each of theobjectives 34, 36, 38 has a field of view, and a light entrance surfacethat captures light reflected from an object and passed through thewindow 61. The viewing direction axes 40, 42, 44 of the optical channels28, 30, 32 are angularly offset relative to the longitudinal axis 20 ofthe imaging scope 12 (e.g., angularly offset by thirty degrees (30°),forty-five degrees (45°), sixty degrees (60°), or another magnitude).The viewing direction axes 40, 42, 44 each extend perpendicular to thelight entrance surface of the objective 34, 36, 38 of the respectiveoptical channel 28, 30, 32. Due to the angular offset of the viewingdirection axes 40, 42, 44 relative to the longitudinal axis 20 of theimaging scope 12, the orientations of the viewing direction axes 40, 42,44 vary as the imaging scope 12 is rotated about its longitudinal axis20. The imaging scope 12 can thus be said to have an “oblique viewing”configuration and/or a “side viewing” configuration. In otherembodiments, the viewing direction axes 40, 42, 44 can be orientedparallel relative to the longitudinal axis 20 of the imaging scope 12.In such embodiments, the imaging scope 12 can be said to have an “endviewing” configuration and/or an angular offset of zero degrees (0°).

FIG. 4 illustrates the distal end of the imaging scope 12 of FIGS. 1-3when the imaging scope 12 is in a first position, and FIG. 5 illustratesthe orientations of the viewing direction axes 40, 42, 44 of the opticalchannels 28, 30, 32 when the imaging scope 12 is in the first position.FIG. 6 illustrates the distal end of the imaging scope 12 when theimaging scope 12 is in a second position in which the imaging scope 12has been rotated about its longitudinal axis 20 by one hundred twentydegrees (120°) compared to the first position (see FIGS. 4 and 5). FIG.7 illustrates the orientations of the viewing direction axes 40, 42, 44of the optical channels 28, 30, 32 when the imaging scope 12 is in thesecond position. FIG. 8 illustrates the distal end of the imaging scope12 when the imaging scope 12 is in a third position in which the imagingscope 12 has been rotated about its longitudinal axis 20 by two hundredforty degrees (240°) compared to the first position (see FIGS. 4 and 5).FIG. 9 illustrates the orientations of the viewing direction axes 40,42, 44 of the optical channels 28, 30, 32 when the imaging scope 12 isin the third position.

In some embodiments, such as those in which the camera 16 is positionedin the housing 51 of the imaging scope 12, each of the at least threeoptical channels 28, 30, 32 further includes a respective imagetransmission device 72, 74, 76 (see FIG. 3) that transmits capturedlight from the respective objectives 34, 36, 38 of the optical channels28, 30, 32 to the camera 16. Referring to FIG. 3, in the illustratedembodiment, each image transmission device 72, 74, 76 includes a rodlens, and each transmits the captured light therethrough in the form ofa captured light beam having a circular cross-sectional shape. The imagetransmission devices 72, 74, 76 can additionally or alternativelyinclude various different types of lenses or light conductors capable oftransmitting the captured light from the objectives 34, 36, 38 to theproximal end portion of the imaging scope 12. The image transmissiondevices 72, 74, 76 can be configured to transmit the captured lighttherethrough in the form of a captured light beam having anothercross-sectional shape that is at least partially circular (e.g., ovular,elliptical, etc.).

The number of optical channels 28, 30, 32 included in the imaging scopeimaging scope 12 can vary. In the embodiments illustrated in FIGS. 1-11,the imaging scope 12 includes three (3) optical channels 28, 30, 32. Inother embodiments, the imaging scope 12 can include four (4) opticalchannels (see FIG. 12 showing four (4) objectives 34, 36, 38, 60); five(5) optical channels (see FIG. 13 showing five (5) objectives 34, 36,38, 60, 62); six (6) optical channels (see FIG. 14 showing six (6)objectives 34, 36, 38, 60, 62, 64), or more than six (6) opticalchannels. The greater the number of optical channels, the greater thenumber of rotational positions of the imaging scope 12 in which a pairof optical channels are parallel with a horizon plane 26.

Referring to FIGS. 2 and 3, in the illustrated embodiments, the imagingscope 12 further includes a plurality of light sources 66 positionedwithin the shaft channel 54 proximate the window 61. The light sources66 are positioned radially between the optical channels 28, 30, 32 andthe shaft wall 52. In other embodiments, the objectives 34, 36, 38 andthe light sources 66 can be arranged in a different manner relative toone another, or in a different manner relative to the distal end portionof the imaging scope 12.

In the illustrated embodiments, the light sources 66 are connected tothe controller 14 via wires 68, 70, and the controller 14 controls(e.g., activates, deactivates) the light sources 66 such that the lightsources 66 selectively illuminate an object by selectively emittingillumination light through the window 61 and out of the distal end ofthe imaging scope 12. In some embodiments, the controller 14 isconfigured to selectively activate one or more light sources 66depending on which optical channels 28, 30, 32 form the activated pair.In such embodiments, the controller 14 can be configured to continuouslychange which light sources 66 are activated in order to keep up withcontinuous changes to which optical channels 28, 30, 32 form theactivated pair.

The camera 16 includes at least two image sensors 82, 84, 86 (e.g.,charge-coupled devices (CODs), complementary metal-oxide semiconductors(CMOSs), etc.). Each of the image sensors 82, 84, 86 includes at least aportion of a light-sensitive surface configured to receive capturedlight from one of the optical channels 28, 30, 32 of the imaging scope12, and each is configured to generate a 2D digital image representativeof such captured light. Although the illustrated embodiments depict theimage sensors 82, 84, 86 as being discrete components relative to oneanother, in other embodiments a single component could form more thanone image sensor. For example, in some embodiments the light sensitivesurface of a CCD or another imaging device could be subdivided intoseveral predetermined portions, with each of the several predeterminedportions forming a separate image sensor. In such embodiments, lightreceived on a first predetermined portion of the light-sensitive surfaceof the CCD could be said to be received by a first image sensor, lightreceived on a second predetermined portion of the light-sensitivesurface of the CCD could be said to be received by a second imagesensor, and so on. In the illustrated embodiments, the number of imagesensors 82, 84, 86 is the same as the number of optical channels 28, 30,32 of the imaging scope 12. In other embodiments, the camera 16 includesonly two (2) image sensors, or another number of image sensors that isfewer than the number of optical channels 28, 30, 32 of the imagingscope 12.

In some embodiments, such as those in which the number of image sensors82, 84, 86 is the same as the number of optical channels 28, 30, 32, theimage sensors 82, 84, 86 can be positionally fixed relative to theoptical channels 28, 30, 32 during operation of the imaging system 10.In such embodiments, each of the optical channels 28, 30, 32 can bepermanently paired with a respective image sensor 82, 84, 86. In otherembodiments, such as those in which the camera 16 includes only two (2)image sensors, the image sensors can be rotatable relative to theoptical channels 28, 30, 32 during operation of the imaging system 10.In such embodiments, a parallel alignment of the two (2) image sensorsrelative to the horizon plane 26 remains fixed during operation of theimaging system 10 (i.e., even during rotation of the imaging scope 12about its longitudinal axis 20 relative to the horizon plane 26).

In the illustrated embodiments, the camera 16 is a video camera, andthus the 2D digital images generated by the image sensors 82, 84, 86 canrepresent one of a plurality of time-sequenced frames of a digitalvideo.

Referring to FIG. 2, in the illustrated embodiments, the controller 14(e.g., a camera control unit (CCU)) is in signal communication with thecamera 16 (in particular, the image sensors 82, 84, 86 of the camera16). As described above, the controller 14 is configured to activate apair of optical channels that is at least as parallel relative to thehorizon plane 26 as any other pair of optical channels among the atleast three optical channels 28, 30, 32. The term “activate,” andvariations thereof, is used herein to describe the process by which thecontroller 14 causes particular optical channels to be those from whichcaptured light is used by the camera 16 to generate the 2D digitalimages. That is, light captured and transmitted through an activatedoptical channel 28, 30, 32 is subsequently received by thelight-sensitive surface of an image sensor 82, 84, 86 of the camera 16,and the respective image sensor 82, 84, 86 generates a 2D digital imagerepresentative thereof. In contrast, light captured and transmittedthrough an optical channel 28, 30, 32 that has not been activated by thecontroller 14 (hereinafter an “inactive” optical channel 28, 30, 32)will not be received by an image sensor 82, 84, 86 of the camera 16.Alternatively, if such light is received by an image sensor 82, 84, 86,the image sensor 82, 84, 86 will not generate a 2D digital imagerepresentative thereof, or it will generate a 2D digital image that willnot be used to generate a 3D digital image.

The controller 14 can automatically activate or deactivate a pair ofoptical channels in various different ways. In embodiments in which thenumber of image sensors 82, 84, 86 included in the camera 16 is the sameas the number of optical channels 28, 30, 32 of the imaging scope 12(see FIG. 2), the controller 14 can activate a particular opticalchannel 28, 30, 32, for example, by instructing a corresponding imagesensor 82, 84, 86 of the camera 16 to generate a 2D digital imagerepresentative of the light received from the particular optical channel28, 30, 32. In other embodiments in which the camera 16 includes onlytwo (2) image sensors and the image sensors are rotatable relative tothe optical channels 28, 30, 32 as described above, the controller 14can activate a particular pair of optical channels 28, 30, 32, forexample, by sending instructions to the camera 16 that causes movementof the image sensors relative to the optical channels 28, 30, 32 (e.g.,via actuation of the image sensors) until the image sensors are alignedwith (i.e., positioned to receive light from) the particular pair ofoptical channels 28, 30, 32.

In the illustrated embodiments, the imaging system 10 further includes agravity sensor 88 (see FIGS. 2 and 11) that sends a data signal to thecontroller 14 regarding the orientation and/or movement of the imagingscope 12 relative to the direction of a gravity vector 48, and thecontroller 14 uses such data to activate a pair of optical channelsaccordingly. The horizon plane 26 can thus be chosen and/or determinedby the controller 14 based on the data signal received from the gravitysensor 88. In the illustrated embodiments, the gravity sensor 88 ispositioned within the housing 51 of the imaging scope 12. In otherembodiments, the gravity sensor 88 could be positioned within the shaft50 of the imaging scope 12, or in another location where the gravitysensor 88 will be rotated together with the imaging scope 12 and/or theoptical channels 28, 30, 32 thereof. The gravity sensor 88 can be in theform of a three-axis acceleration sensor, or in the form of anotherknown device that is capable of performing the functionality describedherein. In some embodiments, the gravity sensor 88 can be turned offmanually and the orientation of the horizon plane 26 can be selectivelychosen and adjusted by a user as described above. In some embodiments,additional sensors like magnetometers and gyroscopes can be used toimprove or correct the measurement of such a gravity sensor 88, as isknown in the prior art. Additional information may be needed, forexample, when the imaging scope 12 is held so that the longitudinal axis20 of the imaging scope 12 is parallel to the direction of a gravityvector 48, as shown in FIG. 10. When the imaging scope 12 is held insuch a position, the gravity sensor 88 may not be able to detect themovement of the imaging scope 12 relative to the gravity vector 48without information from additional sensors (e.g., magnetometers,gyroscopes, etc.).

In some embodiments, the controller 14 is also configured to performknown digital image erecting and digital flip-mirror functions on the 2Ddigital images before transmitting the same to the 3D processor 18.

The functionality of the controller 14 can be implemented usingmechanical, analog and/or digital hardware (e.g., counters, switches,logic devices, memory devices, programmable processors, non-transitorycomputer-readable storage mediums), software, firmware, or a combinationthereof. The controller 14 can perform one or more of the functionsdescribed herein by executing software, which can be stored, forexample, in a memory device. A person having ordinary skill in the artwould be able to adapt (e.g., construct, program) the controller 14 toperform the functionality described herein without undueexperimentation.

The 3D processor 18 is in signal communication with the controller 14,and receives the 2D digital images from the controller 14 and processesthe 2D digital images in a known manner to generate a 3D digital image.In some embodiments, the 3D processor 18 is further configured tocalculate a depth map (not shown) using the 2D digital images. Such adepth map provides a calculation of the relative distances from thewindow 61 at the distal end of the imaging scope 12 to various objectsacross the field of view of the imaging scope 12. The parallax betweenthe 2D digital images allows the 3D processor to calculate such a depthmap.

The functionality of the 3D processor 18 can be implemented using analogand/or digital hardware (e.g., counters, switches, logic devices, memorydevices, programmable processors, non-transitory computer-readablestorage mediums), software, firmware, or a combination thereof. The 3Dprocessor 18 can perform one or more of the functions described hereinby executing software, which can be stored, for example, in a memorydevice. A person having ordinary skill in the art would be able to adapt(e.g., construct, program) the 3D processor 18 to perform thefunctionality described herein without undue experimentation.

Another aspect of the invention involves a method that includes thesteps of: (i) providing an imaging scope 12 that extends along alongitudinal axis 20 between a proximal end portion and a distal endportion thereof, the imaging scope 12 having at least three opticalchannels 28, 30, 32, each including a respective objective 34, 36, 38positioned at the distal end portion of the imaging scope 12 andconfigured to capture light reflected from an object, the objectives 34,36, 38 being annularly-spaced relative to one another and positionedsuch that respective viewing direction axes 40, 42, 44 of the at leastthree optical channels 28, 30, 32 extend at least substantially parallelto one another; (ii) rotating the imaging scope 12 about thelongitudinal axis 20 relative to a horizon plane 26; (iii) activating,among the at least three optical channels 28, 30, 32, a pair of opticalchannels that is at least as parallel relative to the horizon plane 26as any other pair of optical channels among the at least three opticalchannels 28, 30, 32; (iv) generating a first 2D digital imagerepresentative of light captured by a first optical channel of theactivated pair of optical channels, and a second 2D digital imagerepresentative of light captured by a second optical channel of theactivated pair of optical channels; (v) generating a 3D digital imageusing the first 2D digital image and the second 2D digital image.

The present disclosure describes aspects of the invention with referenceto the exemplary embodiments illustrated in the drawings; however,aspects of the invention are not limited to the exemplary embodimentsillustrated in the drawings. It will be apparent to those of ordinaryskill in the art that aspects of the invention include many moreembodiments. Accordingly, aspects of the invention are not to berestricted in light of the exemplary embodiments illustrated in thedrawings. It will also be apparent to those of ordinary skill in the artthat variations and modifications can be made without departing from thetrue scope of the present disclosure. For example, in some instances,one or more features disclosed in connection with one embodiment can beused alone or in combination with one or more features of one or moreother embodiments.

What is claimed is:
 1. An imaging system, comprising: an imaging scope extending along a longitudinal axis between a proximal end portion and a distal end portion thereof, the imaging scope selectively rotatable about the longitudinal axis relative to a horizon plane, the imaging scope having at least three optical channels, each including a respective objective positioned at the distal end portion of the imaging scope, and each configured to capture light reflected from an object, the objectives of the at least three optical channels being annularly-spaced relative to one another and positioned such that respective viewing direction axes of the at least three optical channels extend at least substantially parallel to one another; a controller configured to activate, among the at least three optical channels, a pair of optical channels that is at least as parallel relative to the horizon plane as any other pair of optical channels among the at least three optical channels; a camera configured to generate a first 2D digital image representative of light captured by a first optical channel of the activated pair of optical channels, and a second 2D digital image representative of light captured by a second optical channel of the activated pair of optical channels; and a 3D processor configured to generate a 3D digital image using the first 2D digital image and the second 2D digital image.
 2. The imaging system of claim 1, wherein the pair of optical channels defines a viewing horizon line that is at least as parallel relative to the horizon plane as that of any other pair of optical channels among the at least three optical channels, the viewing horizon line being a line that extends perpendicularly between the respective viewing direction axes of the pair of optical channels.
 3. The imaging system of claim 2, wherein the horizon plane is oriented perpendicular relative to a gravity vector.
 4. The imaging system of claim 2, wherein the horizon plane is oriented parallel relative to a gravity vector.
 5. The imaging system of claim 2, wherein the horizon plane is non-perpendicularly offset relative to a gravity vector.
 6. The imaging system of claim 2, wherein an orientation of the horizon plane is selectively chosen by a user.
 7. The imaging system of claim 2, wherein the horizon plane is determined by the controller based on a data signal received from a gravity sensor, the data signal including data regarding an orientation and/or movement of the imaging scope relative to a direction of a gravity vector.
 8. The imaging system of claim 1, wherein the controller is configured such that, during activation of the pair of optical channels, the controller causes first and second optical channels of the at least three optical channels to be those from which captured light is used by the camera to generate the 2D digital images.
 9. The imaging system of claim 1, wherein light captured and transmitted through a first optical channel of the pair of optical channels is subsequently received by a light-sensitive surface of a first image sensor of the camera, and the first image sensor generates the first 2D digital image representative thereof; and wherein light captured and transmitted through a second optical channel of the pair of optical channels is subsequently received by a light-sensitive surface of a second image sensor of the camera, and the second image sensor generates the second 2D digital image representative thereof.
 10. The imaging system of claim 1, wherein the controller is configured to activate the pair of optical channels by instructing corresponding image sensors of the camera to generate respective 2D digital images representative of light received from first and second optical channels of the pair of optical channels.
 11. The imaging system of claim 1, wherein the controller is configured to activate the pair of optical channels by moving image sensors of the camera relative to the pair of optical channels until the image sensors are aligned with the pair of optical channels.
 12. The imaging system of claim 1, wherein the imaging scope further includes: a shaft that extends in a direction of the longitudinal axis of the imaging scope, the shaft being rigid, and the shaft including a tubular shaft wall and a shaft channel defined by an inner surface of the shaft wall; and a housing connected to a proximal end portion of the shaft.
 13. The imaging system of claim 12, wherein the imaging scope further includes a window disposed at the distal end portion of the shaft, the window being at least substantially transparent.
 14. The imaging system of claim 12, wherein the housing houses the camera; and wherein each of the at least three optical channels includes a respective image transmission device that transmits captured light from the respective objectives of the at least three optical channels to the camera.
 15. The imaging system of claim 12, wherein the camera is housed in a distal end portion of the shaft.
 16. The imaging system of claim 12, wherein at least one of the camera, the controller, and the 3D processor are remotely positioned relative to the imaging scope.
 17. The imaging system of claim 1, wherein the respective viewing direction axes of the at least three optical channels are angularly offset relative to the longitudinal axis of the imaging scope.
 18. The imaging system of claim 1, wherein the camera includes at least two image sensors, each of the at least two image sensors including at least a portion of a light-sensitive surface configured to receive captured light from one of the at least three optical channels, and configured to generate 2D digital images representative of such captured light.
 19. The imaging system of claim 18, wherein a number of image sensors included in the camera is the same as a number of optical channels.
 20. The imaging system of claim 18, wherein the at least two image sensors are positionally fixed relative to the at least three optical channels.
 21. The imaging system of claim 18, wherein the camera includes a number of image sensors that is fewer than the number of optical channels.
 22. The imaging system of claim 21, wherein the at least two image sensors are rotatable relative to the at least three optical channels so that a parallel alignment of the image sensors relative to the horizon plane remains fixed during operation of the imaging system.
 23. The imaging system of claim 22, wherein respective rotational positions of the at least two image sensors relative to the at least three optical channels are controlled by the controller.
 24. The imaging system of claim 1, wherein the respective viewing direction axes of the at least three optical channels each have a fixed angular offset relative to the longitudinal axis of the imaging scope.
 25. An imaging system, comprising: an imaging scope extending along a longitudinal axis between a proximal end portion and a distal end portion thereof, the imaging scope selectively rotatable about the longitudinal axis relative to a horizon plane, the imaging scope having at least three optical channels, each including a respective objective positioned at the distal end portion of the imaging scope, and each configured to capture light reflected from an object, the objectives of the at least three optical channels being annularly-spaced relative to one another and positioned such that respective viewing direction axes of the at least three optical channels extend at least substantially parallel to one another; a controller configured to activate, among the at least three optical channels, a pair of optical channels defining a viewing horizon line that is at least as parallel relative to the horizon plane as that of any other pair of optical channels among the at least three optical channels, the viewing horizon line being a line that extends perpendicularly between the respective viewing direction axes of the pair of optical channels; a camera configured to generate a first 2D digital image representative of light captured by a first optical channel of the activated pair of optical channels, and a second 2D digital image representative of light captured by a second optical channel of the activated pair of optical channels; and a 3D processor configured to generate a 3D digital image using the first 2D digital image and the second 2D digital image.
 26. A method, comprising: providing an imaging scope that extends along a longitudinal axis between a proximal end portion and a distal end portion thereof, the imaging scope having at least three optical channels, each including a respective objective positioned at the distal end portion of the imaging scope, and each configured to capture light reflected from an object, the objectives being annularly-spaced relative to one another and positioned such that respective viewing direction axes of the at least three optical channels extend at least substantially parallel to one another; rotating the imaging scope about the longitudinal axis relative to a horizon plane; activating, among the at least three optical channels, a pair of optical channels that is at least as parallel relative to the horizon plane as any other pair of optical channels among the at least three optical channels; generating a first 2D digital image representative of light captured by a first optical channel of the activated pair of optical channels, and a second 2D digital image representative of light captured by a second optical channel of the activated pair of optical channels; and generating a 3D digital image using the first 2D digital image and the second 2D digital image. 